The first structures in the universe appear to have formed within
A) the newly formed helium.
B) the normal matter.
C) the electromagnetic radiation.
D) the dark matter.
E) the dark energy.
Question 2
It sure is bright everywhere; you've been able to travel around a bit, and it's clear that you are not in a star. Yet it is as bright as looking directly at the Sun.
In your extensive travels through your current surroundings, you cannot find a single neutral atom anywhere, nor can you find a nucleus besides hydrogen or helium. And, while it is hot (a few thousand degrees Kelvin), it is nowhere near the temperature needed for nuclear fusion. Where are you? A) You are in the universe during its first 300,000 years.
B) You are in the universe more than 10100 years in the future.
C) You are in an accretion disk around a supermassive black hole.
D) You are in the central regions of a quasar.
E) You are where the Sun should be located, but about 5 billion years from now.
The internal structures of the eye.
Conduction and gas exchange structures and functions.
Crystal structures of SecY complex in “closed” and “open” conformations
Major Structures of the Ear
The Structures of the Retina
Inappropriate positions of organs and body structures in homeotic mutants